Ms Irby denied revealing her underwear on the flight
A woman who was said to have allowed herself to be fondled by a passenger on a flight to Heathrow Airport has been cleared of being drunk on an aircraft.
Clare Irby, a descendant of the Guinness brewing dynasty, was flying from Bangalore, India, on March 26 when the alleged incidents occurred.
She was accused of being abusive after having up to 10 glasses of wine.
However Ms Irby, 30, of Fulham, west London, told Isleworth Crown Court she was suffering from sleep deprivation.
After the verdict, Ms Irby waved and smiled outside court.
In a statement, her solicitor Richard Slade said: "Clare simply wants to say that she's delighted and relieved that she has been acquitted on this charge.
"She wishes in particular to thank the jury for the time and careful consideration they have given this case and she now wants to be allowed a short period of quiet to enjoy some time with her family, in particular her young son."
During the trial, Ms Irby told the court she felt sorry for passengers who had sat next to her.
She said: "I personally feel sorry for people who sit by me because I know I'm louder than the average person, because I have a child who I care for and have to make sure he behaves as well as he can."
Ms Irby told the court said she was surprised when the captain on the Kingfisher Airlines flight banned her from being served more alcohol and accepted she asked for more wine after the decision had been made.
She also accepted being "rather too curt with the air hostess" and added she was not as polite as usual.
Ms Irby, the daughter of banker Paul Aschan, rejected allegations she had flirted with a fellow passenger or had revealed her underwear while trying to get changed.
She said: "I was a bit relaxed but I was certainly very together. I was exhausted beyond belief.
"I was really, really tired. I would say I was suffering from sleep deprivation at this point."
During the trial, captain Vivek Sondhi told jurors Ms Irby was "on the verge of being dangerous".
Polly O'Callaghan, another passenger on the flight, alleged Ms Irby had been acting flirtatiously with a passenger and alleged that he touched her breast.